Cerebrospinal dysfunction after endovascular stent-grafting via a median sternotomy: the frozen elephant trunk procedure.

BACKGROUND

Endovascular stent grafting through a median sternotomy for a distal arch aneurysm (the frozen elephant trunk procedure) is an alternative to synthetic graft replacement. But spinal cord dysfunction can easily occur as a complication after surgery. Although its cause is uncertain, some attempts at prevention have been instituted. We address the mechanism of spinal cord dysfunction and evaluate the efficacy of our preventive measures.

METHODS

There were 22 men and 2 women with an average age of 71 (59 to 83) years. There were 22 true aneurysms (13 fusiform, nine saccular), one chronic dissection, and one penetrating aortic ulcer. The following strategies for prevention of spinal cord dysfunction were utilized: low flow perfusion through both axillary arteries (n = 10); pigtail catheter guidance (n = 19); use of a shorter graft with anchoring sutures (n = 12); flooding of the operative field with carbon dioxide (n = 7); aortic unclamping (n = 7), and use of ultra-thin woven Dacron grafts (n = 15).

RESULTS

There was no operative mortality, but cerebrospinal dysfunction complicated four cases (17%): one paraplegia, one stroke along the basilar artery, and two cases of temporary spinal cord dysfunction (paresthesia of the right leg and urinary disturbance). Cerebrospinal dysfunction tended to occur in fusiform aneurysms (31%, p = 0.044). Except when low flow antegrade perfusion through both the axillary arteries was utilized, which resulted in no cases of paraplegia or paraparesis (p = 0.064), the methods used for prevention of cerebrospinal dysfunction appeared to have little efficacy.

CONCLUSIONS

Cerebrospinal dysfunction is a serious complication of the frozen elephant trunk procedure. Its cause has not been clarified, but it tends to occur in fusiform-type aneurysms. Antegrade perfusion through both axillary arteries while the aorta is open may be helpful in its prevention.